Starting mechanism for explosive engines



July 4, 1939fv J. L. YARIAN ,67

STARTING MECHANISM FOR EXPLOSIVE ENGINES Filed Dec. 18, 1936 2 Sheets-Sheet l Jaml Farm,

July 4, 19396 YARlAN 2,164,673

STARTING MECHANISM FOR EXPLOSIVE ENGINES Filed Dec. 18, 1936 2 Sheets-Sheet 2 Patented July 4, 1939 UNITED STATES PATENT OFFICE STARTING MECHANISM FOR EXPLOSIVE ENGINES Application December 18, 1936, Serial No. 116,635

Claims.

This invention relates to manually-operated starting mechanism for internal combustion engines, and is more particularly concerned with starters of this type designed for incorporation in motors employed for operating washing machines and similar light machinery.

Motors of the type referred to must be compact and occupy relatively small space, due to the necessity for housing the same in the restricted area afforded by the machines with which they are used. It is necessary, therefore, that starting mechanism for these motors also must be compact and simple in order not to cumber the motors with excess parts or otherwise require greater space than that allotted for accommodating the motor.

The present invention contemplates a novel starting mechanism which answers the requirements indicated, and one which is easily incorporated as a unitary part of the engine structure. When thus built into the engine structure the starting mechanism, in the main, is free from exposure and impairment, insures long service and precludes injury to users as the mechanism is operated.

Other objects and advantages will appear as the nature of the improvements is better understood, the invention consisting substantially in the novel construction, combination and arrangement of parts as will be hereinafter fully described, illustrated in the accompanying drawings and pointed out in the appended claims.

The form of the invention herein shown and described is believed to be a preferred embodiment thereof, but it is to be understood that the same is susceptible to change, modification and variation. The present disclosure, therefore, is to be considered as illustrative and not as imposing restriction or limitation on the invention.

In the drawings,

Fig. 1 is a side elevation of an internal combustion engine in which is incorporated the herein described starting mechanism;

Fig. 2 is a vertical transverse sectional View of the engine illustrating the gear connections between the operating lever and the crank shaft of the engine; and

Fig. 3 is a detail sectional view, as on the line 3 3, Fig. 1.

Referring in detail to the accompanying drawings, the numeral I0 designates the cylinder of an internal combustion engine of the air-cooled type and of a construction designed for driving washing machines and similar light machinery. The crank shaft thereof is designated by the numeral I I, and the cam shaft by the numeral I2. The construction of the engine and its parts forms no part of the present invention, except as the engine structure may be modified for incorporating therein the herein described starting mech- 5 anism.

A foot-operated lever I3 is mounted on the outside of the engine casing, as by a stud I4, on which the lever may be rocked, a spring cotter pin I 5, or its equivalent, serving to hold the lever on the stud. The inner end of the lever I3 is formed to provide a segment gear I6, while the outer end has a toothed contact head I! to which the foot of the operator may be applied when it is desired to operate the lever.

The segment gear I6 engages a pinion I8 that is carried by a bushing I9, said bushing being rotatably mounted on a reduced neck formed on a hub 21 through which the cam shaft I 2 projects, said hub having a shoulder 22 against 20 which the inner end of the bushing l9 abuts. At the outer end of the bushing I9 the same is provided with a reduced neck 23. The bushing I9 freely rotates on the neck 20 of the hub 2|.

On the cam shaft I2, but Within the engine casing, is mounted also a gear of larger diameter, designated 24, and said gear 24 meshes with a pinion 25 that is carried by the crank shaft II. The pinion 25 also is within the engine casing, and the ratio of said gears 24 and 25 is 2 to 1, thus enabling the crank shaft to be turned over at greater speed than the cam shaft. This is conducive to quicker ignition of the explosive charge with a resultant more rapid starting of the engine.

A coil spring 26 surrounds the axis of the lever I3 at the outside of the casing, one end thereof being anchored to the exterior of the casing, as at 21, while the other end of said spring 26 is connected to the segment gear I6, as at 28. 0

On the extremity of the cam shaft I2, being the extremity thereof which projects at the exterior of the engine casing, is mounted a cylindrical cap 29, the same being rigidly fastened to the cam shaft I 2 by a pin 30. This cap 29 houses a spiral spring 3 l. The spring 31 is loosely coiled and fits within the cap 29 with just sufficient clearance between the spring and the inner wall of the cap so that when the engine is operating there will be no engagement between the outer surfaces of the coils of the spring and the wall of the cap. One end of the spring 3| is fixedly connected to the neck 23 of the bushing I9, as at 32, so that as the foot lever I3 is depressed the bushing I9 is rotated to expand the spring 3| into Cil engagement with the inner wall of the cap 29 and thereby create a binding action between the spring and the cap. In such position of the parts the cam shaft I2 will be rotated and, through the intermediate gears I8, 24 and 25, the crank shaft ll also will be rotated. The spring 25 controls the movement of the lever l3, and when pressure is removed from the lever it returns to its normal or elevated position, the spring 26 effecting such return.

It will also be understood that on the return movement of the lever l3 to its normal position the binding action of the spring 3| against the inner wall of the cap 29 will be released, and the cap 29 may rotate freely with respect to the spring when the shaft i2 is operating under the power of the engine.

To cushion the return of the lever i3 to normal position under the reactance of the spring 26 after release of pressure from the lever IS, an elastic buffer 32 is employed. This is held on the engine frame by a retaining cup 33, the buifer 32 being in the path of movement of the lever l3 and against which said lever will contact when it moves back to its normal position. Preferably the buffer 32 is formed of rubber.

The bushing NJ, the cap 29 and the spring 3! constitute a clutch between the cam shaft 52 and the operating lever l3 which acts to lock the lever in driving relation to said shaft and automatically to interrupt that relation after the engine has been started. As such clutch, the bushing l9 serves as the driving member, the cap 29 as the driven member and the spring 35 as the intermediate coupling member for the driving and driven members. The bushing it and the cap 29 are in line with each other, the open end of the cap fitting over the neck 23 of the bushing and thus enclosing also the spring 3i so as to protect the latter against injury and accumulations of dirt.

From the foregoing description it will be apparent that to start the engine the lever I3 is depressed to swing the segment gear E5 on its pivot. The engagement of the gear l6 with the pinion l8 rotates the bushing l9 and this will expand the spring 3! into frictional engagement with the cap 29 which, being fixedly connected to the cam shaft l2, will operate the gears 2 and 25 so as to turn over the crank shaft II. If, on the first depression of the lever E3, the explosive charge is not fired, the lever maybe returned to its normal raised position and again depressed, and this operation repeated until the charge is fired and the engine is under operation. Because the bushing H! has free rotation on the cam shaft l2, it is obvious that when the speed of rotation of that shaft has increased to the point where the cap 29 will break its frictional engagement with the spring 3i, the cap 29 will overrun the spring 3 1. Thus, the gripping action of the spring 3| in relation to the cap 29 automatically will be interrupted.

I claim:

1. In starting mechanism of the class described, wherein is embodied a rotatable shaft in coupled relation to the piston of an explosive engine with one of its ends projecting at the exterior of the engine casing, and also including an operating lever pivotally mounted on the engine casing and provided with a segment gear, a toothed driving member carried by said shaft and freely rotatable thereon, said driving member having a reduced neck at one of its ends, said driving member being engaged by the segment gear of said operating lever, a driven member directly mounted on said shaft in line with said driving member and fixedly connected to said shaft, said driven member being open at one of its ends and tubular in form, the open end of said driven member receiving the neck of said driving member, and means within said tubular driven member connected to the neck of said driving member and serving to connect the driving member to the driven member when said operating lever is depressed.

Z. In starting mechanism of the class described, wherein is embodied a rotatable shaft in coupled relation to the piston of an explosive engine with one of its ends projecting at the exterior of the engine casing, and also including an operating lever pivotally mounted on the engine casing and provided with a segment gear, a toothed driving member carried by the projecting end of said shaft and freely rotatable thereon, one end of said driving member being reduced to form a neck, said driving member being engaged by the segment gear of said operating lever, a driven member directly mounted on said shaft in line with said driving member, said driven member being open at one of its ends and tubular in form, the open end of said driven member overlapping the reduced neck of the driving member, and a coil spring within said tubular driven member having one of its ends connected to the reduced neck of the driving member and expansible into engagement with said driven member for con necting the latter to said driving member when said operating lever is depressed.

3. In starting mechanism of the class described, wherein is embodied a rotatable shaft in coupled relation to the piston of an explosive engine with one of its ends projecting at the exterior of the engine casing, and also including an operating lever pivotally mounted on the engine casing and provided with a segment gear, a toothed bushing carried by said shaft and freely rotatable thereon, said bushing being engaged by the segment gear of said operating lever and having a reduced neck at one of its ends, a cap directly mounted on said shaft in line with said bushing and fixedly connected to said shaft, the open end of said cap overlapping and receiving the reduced neck ofsaid bushing and means within said cap connected to said bushing for connecting the latter to said cap when, said operating lever is depressed.

4. In starting mechanism of the class described, wherein is embodied a rotatable shaft in coupled relation to the piston of an explosive engine with one of its ends projecting at the exterior of the engine casing, and also including an operating lever pivotally mounted on the engine casing and provided with a segment gear, a toothed bushing carried by the projecting end of said shaft and freely rotatable thereon, said bushing being engaged by the segment gear of said operating lever and having a reduced neck at one of its ends, a cap directly mounted on said shaft in line with said bushing and fixedly connected to said shaft, the open end of said cap being adjacent to said bushing and overlapping the reduced neck of said bushing, and expansible means within said cap connected to said bushing for connecting the latter to said cap when said operating lever is depressed.

5. In starting mechanism of the class described, wherein is embodied a rotatable shaft in coupled relation to the piston of an explosive engine with one of its ends projecting at the exterior of the engine casing, and also including an operating lever pivotally mounted on the engineoasing and provided with a segment gear, a cap mounted on the outer end of said shaft and having its inner end open, said cap being fixedly connected to said shaft and constituting a driven member, a toothed bushing also carried by the projecting end of said shaft and freely movable thereon, said toothed bushing constituting a driving member and having a reduced neck at its outer end fitting in and received by the inner open end of said cap, said bushing being arranged between said cap and the engine casing for engagement of the teeth thereof by said segment gear, and means within said cap connected to said bushing for connecting the latter to said cap when said operating lever is depressed.

JAMES L. YARIAN. 

